Auditory & Vestibular Flashcards
what is hearing
neural perception of sound energy
what is sound
audible disturbance of molecules in a medium (air/water)
what kind of wave - sound
longitudinal
what is frequency and amplitude
frequency - pitch (low = low)
amplitude - volume (high/low pressure)
what is unit sound
decibel (dB)
what is audible range
~20Hz to 20kHz
what si the external ear for
air
collection
what si the middle ear for
bone
conc
what is the inner ear for
fluid
detection
what does the middle ear transmit
vibrations via ossicles to inner ear - mechanical concentrator and transmitter
what does inner ear transmit
cochlea traduces vibrations to electrical impulse
what are the layers of tymp mem
skin
CT
resp epi
name parts of ear
external ear EAM tymp mem middle ear middle ear ossicles inner ear IAM cochlea nasopharyngeal tube
what are the ossicles
tiny bones
malleus
incus
stapes
what are the ossicle joints
synovial joints
what si the conc of sound energy
big mem of tymp mem goes to small space meaning intensity and conc increase
not amplify
what fluid fills outer channels
perilymph
what fluid fills inner channels
endolymph
what is perilymph
essentially extracellular fluid - Na ions
what does fluid in ear system allow
conducting nerve AP’s
what is the helocotremA
where two outer tubules meet at ape of cochlea
what are the three tubes of cochlea
scala vestiboli
scala tympani
scala media (middle)
what si the purpose of round window
transmit pressure in closed tube and dissipates it
deformable
what is the central part of cochlea
modulus bone
what are the hair cells in the ear
single row inner hairs used for hearing
outer hairs few used for sound location
what is the collection of hair cells called
organ of corti
what is stria vascular
sp epi on lateral wall of media producing endolymph
what is tonotopicity
cochlear organised in terms of high and low tones
high tones incase cochlea whilst low tones at helicotrema
what is the route for CN 8
sup olivary nun trapezoid body lateral lemniscus medial lemniscus inf colliculus medial geniculate body auditory radiation
why does nerve go to sup olivary nun
for localisation and space diff intensities
what is trapezoid body
crossing point of axons from one side to other
what happens in lateral lemnisus
synapse
how does tonotopicity affect structure
forrad and lateral - lower tones received
post and medial - high frequency
what ar the 3 components of the labyrinth
utricle
saccule
semicircular ducts
what do the components of the labrtinht have
receptors for movement and her cells fro trasnudcing sound
where are the receps for angular rectption
semicircular canals
what si the cupola
gelatinous goo on top hair cells
what is cupola for
if turn head water push cupola set off AP’s giving detcetio of head movement
what are the semicircular canals to each other
90 degrees
how are the semicircular canals arranged
ant, post, lat
canted in sp way not anatomical planes
how do semicircular ducts work
in pairs
what is ant paired with
post
when turning head what fires
turn left
left increases fire
right decrease fire
what is macula
sensory plaque in saccule and utricle
what does macula detect
linear acceleration and head position
what are otoliths
grains calcium carb
on top gelatinous goo
heavier than water so can tell stationary dtection
what is path of vestibular fibres
ganglion nuclei medial longitudinal fascicles - extra ocular muscle activated flocularnodular node -cerebellum thalamus cortex
what is doll’s eye manoeuvre
vestibule-ocular reflex
off ride effect on eyes fast flick to side and slow back
what si projection of vestibular info to cortex
bilateral
